/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.io.gcp.spanner;



import com.google.cloud.spanner.Mutation;

import com.bff.gaia.unified.vendor.guava.com.google.common.base.Objects;

import com.bff.gaia.unified.vendor.guava.com.google.common.collect.ImmutableList;



import java.io.Serializable;

import java.util.Arrays;

import java.util.Iterator;

import java.util.List;



/**

 * A bundle of mutations that must be submitted atomically.

 *

 * <p>One of the mutations is chosen to be "primary", and can be used to determine partitions.

 */

public final class MutationGroup implements Serializable, Iterable<Mutation> {

  private final ImmutableList<Mutation> mutations;



  /**

   * Creates a new group.

   *

   * @param primary a primary mutation.

   * @param other other mutations, usually interleaved in parent.

   * @return new mutation group.

   */

  public static MutationGroup create(Mutation primary, Mutation... other) {

    return create(primary, Arrays.asList(other));

  }



  public static MutationGroup create(Mutation primary, Iterable<Mutation> other) {

    return new MutationGroup(ImmutableList.<Mutation>builder().add(primary).addAll(other).build());

  }



  @Override

  public Iterator<Mutation> iterator() {

    return mutations.iterator();

  }



  private MutationGroup(ImmutableList<Mutation> mutations) {

    this.mutations = mutations;

  }



  public Mutation primary() {

    return mutations.get(0);

  }



  public List<Mutation> attached() {

    return mutations.subList(1, mutations.size());

  }



  @Override

  public boolean equals(Object o) {

    if (this == o) {

      return true;

    }

    if (o == null || getClass() != o.getClass()) {

      return false;

    }

    MutationGroup mutations1 = (MutationGroup) o;

    return Objects.equal(mutations, mutations1.mutations);

  }



  @Override

  public int hashCode() {

    return Objects.hashCode(mutations);

  }



  @Override

  public String toString() {

    StringBuilder sb = new StringBuilder("MutationGroup(");

    sb.append(mutations);

    sb.append(")");

    return sb.toString();

  }

}